1. Field of the Invention
The present invention relates to a foundation shock eliminator, and more particularly to a foundation shock eliminator that will dissipate and absorb efficiently both vertical and horizontal shocks to a structure or a machine.
2. Description of Related Art
Vibration control and shock reduction are fundamental concerns in the construction of structures, machines and industrial manufacturing instruments. This can concern vibration and shocks from seismic events or even low intensity events such as subway trains passing below structures. Although the subway train shocks are relatively predictable in their direction, intensity and even timing, the same is not true for earthquakes that can vary enormously, thereby providing particular difficulty to civil engineers. Diminishing the effect of shocks on objects is achieved primarily by isolating the shocks or absorbing the shocks.
Shocks, such as seismic shocks or low intensity shocks will influence adversely qualities of high precision electronic products during the fabrication of the electronic products. Therefore, reduction of the effects of shock transmitted to the high precision manufacturing machines in electronic industries is always an important concern.
A conventional foundation shock eliminator in accordance with prior art is generally mounted between the rigid foundation and structures or the floor and machines. The conventional foundation shock eliminator is made of steel and comprises an upper block, a lower stationary base and a roller.
The upper block and the lower stationary base may be rectangular, square, round or polygonal and have respectively concave inner surfaces. The lower stationary base is fastened to the rigid foundation such as ground or the floor by fasteners such as bolts. The upper block supports the bottom of the structure or machines, is supported by the roller and is movable relative to the lower stationary base. The concave inner surfaces of the upper block and the lower stationary base face each other.
The roller can be a rolling ball and is mounted between the two concave inner surfaces, whereby the ball rolls on the concave inner surface of the lower stationary base and supports the concave inner surface of the upper block.
Consequently, the conventional foundation shock eliminator will reduce the effect of shocks, such as from earthquakes, transmitted to the structures or machines when the ground or floor undergoes shocks with the relative movements of the upper block.
However, the conventional foundation shock eliminator cannot completely diminish the effect of shocks transmitted via the ground or the floor enough to keep the structures from collapsing or the machines from being influenced adversely by the shocks. Since the roller of the conventional foundation shock eliminator only reduces the horizontal component of shocks and does nothing to reduce the vertical component of shocks, the applications and usage of the conventional foundation shock eliminators are restricted.
To overcome the shortcomings, the present invention provides an improved foundation shock eliminator to mitigate or obviate the aforementioned problems.